https://github.com/sindresorhus/refined-github/blob/master/source/features/show-whitespace.css

As you can see I'm using the GitHub-Dark Theme but the whitespace are not really visible with this theam 🙁
When I look into the source code, I can see a hard-coded fill. Can we make this configurable or overridable in any way?
I tried to just override it in Chrome via DevTools, but I had no luck 🤔
Don't know what I'm doing wrong or if this is even the correct color setting